<!DOCTYPE html>
<html style="height: 100%">
<head>

<meta name="viewport" content="width=800">
<style>
html { font-size: 16px; }
body { width: 800px; margin: 0; overflow-y: hidden; }
</style>

</head>
<body style="height: 100%">

<div style="font-size: 2.5rem">
    This text should be autosized to 40px computed font-size, since the constrained height on the html and body elements gets ignored (a hack to fix some sites that appear to set this accidentally).<br>
	Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
</div>

</body>
</html>